Try to fix bug 263732

I have a question on the code.

The commandline is parsed by the commandline parser from Qt. But the arguments are passed around using a string. Everytime a function needs to check for an argument, it deserializes the string to retrieve the value.

That workflow has the advantage, that it requires only a QString to pass the data to other functions.
I prefer to have a data structure, which contains the arguments as fields.

Is there any other disadvantage in using a struct instead of a string?

Furthermore several tests fail. Is that intended, or forgotten? I did not yet dig deeper into the codebase to understand, what the tests do.